Oil tank washing machine

ABSTRACT

The machine for washing the interior surface of a hollow structure includes a head assembly mounted for rotation about a first axis. A wash fluid discharge head is mounted on head assembly for rotation with respect thereto about a second axis at an angle to said first axis. The head assembly has a passage for receiving and transferring wash fluid to the wash fluid discharge head. A wash fluid actuated rotary drive means is mounted on the head assembly externally of the passage. A fluid feed passage extends from the first passage to the drive means. Transmission means is connected to the drive means to effect simultaneous rotational movement of the head assembly about the first axis and the wash fluid discharge head about the second axis. The transmission means includes means for effecting intermittent accelerations or decelerations in the rotational speed of the wash fluid discharge head relative to the rotational speed of the head assembly.

United States Patent Inventor Robert Benham Bonfield Goring-by-Sea,England Appl. No. 788,421 Filed Jan. 2, 1969 Patented June 15, 1971Assignee Dasic Equipment Limited Southampton, England Priority Jan. 9,1968 Great Britain 1264/68 OIL TANK WASHING MACHINE 12 Claims, 8 DrawingFigs.

Primary Examiner- Lloyd L. King AttorneyAlexander & Dowel] ABSTRACT: Themachine for washing the interior surface of a hollow structure includesa head assembly mounted for rotation about a first axis. A wash fluiddischarge head is mounted on head assembly for rotation with respectthereto about a second axis at an angle to said first axis. The headassembly has a passage for receiving and transferring wash fluid to thewash fluid discharge head. A wash fluid actuated rotary drive means ismounted on 'the head assembly externally of the passage. A fluid feedpassage extends from the first passage to the drive means. Transmissionmeans is connected to the drive means to effect simultaneous rotationalmovement of the head assembly about the first axis and the wash fluiddischarge head about the second axis. The transmission means includesmeans for effecting intermittent accelerations or decelerations in therotational speed of the wash fluid discharge head relative to therotational speed of the head assembly.

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WWW W OIL TANK WASHING MACHINE DESCRIPTION OF THE INVENTION Theinvention relates to machines for washing the interior surfaces ofhollow structures, and particularly to machines for washing theinteriors of the tanks of marine oil tanks with high pressure fluidjets.

The invention provides a machine for washing the interior surface of ahollow structure comprising a head assembly, means for mounting the headassembly for rotation about a first axis, a wash fluid discharge headmounted on said head assembly for rotation with respect thereto about asecond axis at an angle to said first axis, a passage in said headassembly for receiving and transferring wash fluid to said wash fluiddischarge head, wash fluid actuated rotary drive means mounted on saidheadassembly externally of said passage, a fluid feed passage extendingfrom said passage to said drive means, and transmission means connectedto said drive means to effect simultaneous rotational movement of saidhead assembly about said first axis and said wash fluid discharge headabout said second axis, said transmission means including means foreffecting intermittent accelerations or decelerations in the rotationalspeed of said wash fluid discharge head relative to the rotational speedof said head assembly.

In consequence of the accelerations or decelerations, jets of wash fluidfrom said wash fluid discharge head are precessed slightly at eachpassage around the interior surface of the hollow structure washed bythe machine so that the whole of said interior surface can beeffectively washed.

The invention may further comprise the features hereinafter describedwith reference to the accompanying drawing in which:

FIG. 1 is a perspective view of a machine according to the invention,

FIG. 2 is a sectional side elevation on the line II-II of FIG. 1,

FIG. 3 is a sectional plan view on the line IIlIII of FIG. 2,

FIG. 4 is a sectional side elevation on the line IV-IV of FIG.

FIG. 5 is a sectional side elevation of a modified embodi-. ment of theinvention, the Pelton wheel and transmission system being omitted fromthe drawing in order to illustrate the modifications with greaterclarity,

FIG. 6 is a sectional side elevation of a further modified embodiment ofthe invention,

FIG. 7 is a sectional plan view on the line VII-VII of FIG. 6, and

FIG. 8 is a sectional plan view on the line-VlIl-VIII of FIG. 6.

Referring first to FIG. 1, the machine comprises a wash head bodyportion 1 having a wash fluid discharge head 2 mounted thereon forrotation about a horizontal axis. The discharge head 2 comprises twooppositely directed nozzles 3. The body portion 1 is mounted forrotation at the lower end of a wash fluid supply tube 4 terminating in aflange 5.

Referring now to FIG. 2 to 4, the machine comprises a stub pipe 6 havinga flange 6a at the upper end thereof for facilitating bolted connectionto the flange 5 of the supply tube 4. At its lower end, the stub pipe 6is provided internally witha spider 7 from which depends a static shaft8 coaxial with the stub pipe 6.

Between the flange 6a and the spider 7, the stub pipe 6 carries agraduated filter structure 6b. The comprises a series of spaced gauges,the mesh sizes of which decrease in a direction from the flange 6atowards the spider 7.

The body portion 1 comprises a neck portion 9 dimensioned for rotationon the lower end the stub pipe 6 and provided with a labyrinth gland I0.The body portion-I is divided into two chambers by an internal wall,namely a wash fluid chamber 12 and a precess and drive gear chamber 13.The shaft 8 extends through a gland structure 14 in the wall which isvented from a central position by a vent l5.

The chamber 12 is defined in part by the neck portion 9 and comprises aninclined passage 16 which terminates in a horizontal bore 17. At theinner end of the bore 17, a small concentric bore 18 is provided intothe chamber 13. Journaled for rotation in the bores 17 and 18respectively are a hollow cylindrical body 19, forming part of thedischarge head 2, and a stub shaft 20 extending therefrom, the bores 17and 18 being provided with labyrinth glands 21 and 22, and O-ring sealsat 2111.

The end of the stub shaft 20 extending into the chamber 13 has a bevelcrown wheel 23 keyed thereon and retained by a nut.

The cylindrical body 19 has an inner end wall 25, an outer end wall 26an apertures 24 in the cylindrical wall thereof which apertures 24 sweepacross the end of the passageway 16 during rotation of the cylindricalbody 19. At its outer end, the cylindrical body 19 extends beyond thebody portion 1 and carries the two nozzles 3 which extend indiametrically opposite directions. If desired the nozzles may beslightly offset on opposite sides of the diametric centerline of thecylindrical body 19 so as to provide an assisting torque during rotationof the discharge head 2.

At its lower end, the static shaft 8 is journaled in a thrust bearing 27set in a lower cover 28 of the body portion 1 and adapted to transferthe full weight of the body portion 1 and discharge head 2 machine ontothe shaft 8. The thrust bearing 27 may comprise a ball race generally asshown in FIG. 2 or a dry lubricated bearing may be used, for exampleutilizing sintered bronze/polytetrafluoroethylene/lead bearing surfaces.A bearing cover 27a is provided to protect the bearing.

A worm wheel 29 is secured by a shear pin 30 on the shaft 8 at aposition within the chamber 13 just above the bearing 27. The worm wheel29 carries an upwardly extendingstepped sleeve bushing 31 on which iskeyed a quadrant plate 32.

Mounted for rotation on the shaft 8 above the quadrant plate 32 is apinion 33 having an upwardly extending sleeve bushing 34 formed as abevel pinion 35 at its upper end, the bevel pinion 3S meshing with thecrown wheel 23 mounted on the stub shaft 20.

At a position spaced radially from the shaft 8, the quadrant plate 32 isbored to receive a sleeve bearing 36 in which a spindle 37 is journaled.At its lower end the spindle 37 carries a pinion 39 which meshes with apinion 40 (FIGS. 3 and 4). The pinion 40 is mounted for rotation on aspindle 41 set in the quadrant plate 32 and is formed integrally at thelower surface thereof with a star wheel 42 having four lobes 43.

Mounted in the body portion 1 in horizontal alignment with the starwheel 42 is a strike pin 74 which extends inwardly to such a positionthat upon rotation the body portion 1 about thespindle 8 (as describedbelow), the pin 74 strikes one of the lobes 43 and causes partialrotation of the star wheel 42, this partial rotation being transmittedthrough the gears 40, 39, 38, 33, 35 and 23 to the head 19, the overallreduction being 9:] to effect an acceleration of deceleration of thegear 35, the gear 23 and thus of the rotational speed of the wash fluiddischarge head.

The worm wheel 29 meshes with a worm 44 keyed to one end of a shaft 45.A pinion 46 keyed to the other end of the shaft 45 meshes with an idlerpinion which in turn meshes with a pinion 47 keyed to the end of a shaft48. At the other end of the shaft 48 is keyed a pinion 49 which mesheswith a pinion 50 keyed to a drive shaft 51. The shaft 51 extends throughlabyrinth sleeve bearings 52 in the outer wall of the body portion 1 andhas keyed to the other end thereof a Pelton wheel 53. The bearings 52are vented from a midposition by a vent 54.

The Pelton wheel 53 is enclosed in a cover 55 bolted to the bodyportion 1. The cover 55 carries a pipe union 56 in one wall thereof towhich a nozzle 57 is secured for operation of the Pelton wheel. A pipe58 extends from the other end of the pipe union 56 to a second pipeunion 59 mounted in the wall of the wash fluid chamber 12. A gaugefilter 59a is provided as shown to prevent any particulate material fromentering the pipe 59 that may have passed the filter 6b.

A discharge vent 60 is proved In the cover 55 for exhaust fluid from thePelton wheel.

In operation, the machine is advantageously mounted as a permanentinstallation in a tank to be washed with the flange 6a being connectedto the flange of the wash fluid supply pipe 4.

As soon as wash fluid under pressure enters the chamber 12 from the pipe4, a small proportion is bled oflthrough the pipe union 59 and pipe 58to the nozzle 57. The remainder of the wash fluid is fed down thepassage 16 and through the apertures 24 into the cylindrical body 19where it is discharged through the nozzles 3. The fluid dischargedthrough the nozzle 57 impinges on the buckets of the Pelton wheel 53 tocause rotation thereof at a maximum speed of 2,600 r.p.m. and is thendischarged through the vent 60 in the cover 55.

The rotation of the Pelton wheel is transmitted through the gear train50, 49, 47 and 46 to the worm 44 so as to preferably provide a 100:]reduction from the speed of the Pelton wheel. Since the wonn wheel 29 isfixed by the shear pin 30 of the shaft 8, the rotation of the wormcauses the body 1 to rotate about the shaft 8.

The initial rotation of the body 1 causes rotational movement to beimparted to the crown wheel 23 due to its engagement with the levelpinion 35.

A friction pad 320 is set into the lower side of the quadrant plate 32so as to bear on the pinion 39 and prevent slip and consequent rotationof the gears 38 and 33 which would check this rotational movement. Thepad 320 is loaded by springs 32b set in bores in the quadrant plate andadjustable by grub screws.

As the body continues to move round the shaft 8, the striker pin 74,strikes one of the lobes 43 of the star wheel 42 and causes, through thegear train 40, 39, 38, 33, 35 and 23 a momentary acceleration of thecylindrical body 19. The frequency with which this acceleration occurscan be varied by increasing or decreasing the number of lobes 43 on thestar wheel and/or the number of striker pins 44 set in the body 1.

The striker pin 44 and/or the lobes 43 may also be longitudinally and/orradially adjustable respectively so as to regulate the frequency ofstriking and length of contact (and therefore extent of movement of thestar wheel. The acceleration can also be varied by changing the gearratios between the star wheel 42 and the crown wheel 23.

In a preferred embodiment, the body portion 1 rotates about the verticalshaft 8 at a speed of 5 revolutions per minute or less and the washfluid discharge head 2 rotates at a speed approximately one-third of butvariable in respect of, the speed of the body portion 1.

The paths of impingement of the jets from the nozzles 3 on the walls ofthe tank are thus precessed slightly at each passage so that eventuallythe whole of the tank surface is washed.

Furthermore, by arranging the wash fluid discharge head 2 to rotate moreslowly than the body portion 1, the paths if impingement have a moderateslope and the jets are more effective in removing residues fromhorizontal surfaces in the tank.

The pinion and star wheel 42 may be arranged for easy removal from themachine after removal of the cover 28 so that the star wheel 42 or thegear train between the star wheel and the crown wheel 23 may be changedto provide a ratio of rational speeds between the body portion 1 and thewash fluid discharge head to suit particular operating requirements.

In the embodiment described above, the number of teeth on the variousgears were as follows.

In the modified embodiment of FIG. 5, the parts which are analogous tothe construction of FIGS. 1 to 4 are given the same reference numerals,(the Pelton wheel, transmission and precess gearing being omitted forclarity).

This embodiment provides a modified body portion 1 and discharge head 2which incorporate a clutch and means wfi'etet' 'reatvitflartfiPanda's/Hearts ltrifitemany of the bod T: this end, the crown wheel 23is mounted on one end ofa shaft 61 by a nut 62. The shaft 61 extendsthrough the bore 18 and coaxially with the bore 17 in the body 1 to aposition beyond the end of the bore 17. At its outer end, one element 63of a core clutch is mounted on the shaft 61. At a position adjacent thebore 18, a gland member 64 is keyed to the shaft 61, the member 64incorporating a number of seals to prevent ingress of water to andthrough the bore 18.

The wash head 2 is mounted towards the outer end of the shaft 61 for feerotation thereon when the core clutch is disengaged between the coreclutch element 63 and the end of the bore 17. The wash head 2 has twonozzles 3 extending radially therefrom and a cylindrical boss portion 65extending along the bore 17 as far as the passage 16. At its outer facethe boss portion 65 is formed with a core clutch face 66 adapted tocooperate with the element 63. The outer surface of the boss portion 65is provided with a ring seal 67 and sufficient clearance is providedbetween the clutch element 63 and the end of the bore 17 to permitlimited axial sliding movement of the wash head 2 on the shaft 61.

At a position inwardly of the seal 67, the boss portion 65 is providedwith an external annular recess 68 into which a series of holes 68a ventfrom the interior of the boss. The holes 68 also act as a strainer. Apassage 69 extends from the annular zone in which the recess 68 in theboss rotates and through the body 1. The other end of the passage 69connects with the nozzle member 57 mounted in the Pelton wheelcompartment (not shown) for actuation of the Pelton wheel.

The passage 69 is preferably formed as an integral part of the bodycasting although an external pipe may be provided if required similar tothe pipe 58 of FIG. 1.

Turning now to FIGS. 6 to 8 the embodiment shown comprises a wash headbody portion 101 having a wash fluid discharge head 102 mounted thereonfor rotation about a horizontal axis therein. The wash fluid dischargedhead 102 having two oppositely directed nozzles 103.

The body portion 101 comprises a flange 104 adapted to be bolted to acooperating flange (not shown) provided on the end of a wash fluidsupply pipe. A first element 105 of a clutch is secured on the undersideof the flange 104 by set screws, the clutch face being formed by thelower surface 106 of an internal annular recess 107 formed therein. AnO-ring seal 108 is also provided in the element 105 above the recess107.

The O-ring seal 108 is engaged by the upper end of an entry pipe 109which also has an external annular flange 110 engaging in the recess107, the lower face 111 of the flange 110 forming the second clutchsurface.

The entry pipe also has a spider 112 mounted internally therein, fromwhich depends a static shaft 113 coaxial with the entry pipe 109.

A neck portion 114 of the body portion 1 is dimensioned for rotation onthe lower end of the entry pipe 109, an O-ring seal 1 15 being providedbetween the two members.

The body portion 1 is divided by internal walls 1 16, 117 and 118 into awash fluid chamber 119, a precess gear chamber 120, a transmission gearchamber 121 and a Pelton wheel compartment 122, the chambers beinggenerally arranged in sequence one beneath the other.

The chamber 119 is defined in part by the entry pipe 109 and alsocomprises an inclined passage 123 which terminates in a horizontal bore124 At the inner end of bore 124, a small concentric bore 125 isprovided into the chamber 120. Journaled for rotation in the small bore125 is a shaft 126 having a bevel crown wheel 127 keyed to the endextending into the chamber and secured by a nut. The bore is providedwith a labyrinth gland 128 around the shaft 126. A flange member 129keyed onto the shaft 126 adjacent the bore 125 and has an O-ring seal130 which seals against a cylindrical surface 131 forming part ofinternal wall 116. The gland 128 and seal 130 prevent ingress of waterthrough the bore 125 to the chamber 120.

The shaft 126 extends beyond the end of the bore 124 and at its outerend carries one element 132 of a core clutch secured by a nut 1320. Thewash head 102 is mounted for free rotation on the shaft 126 when theclutch is disengaged between the core clutch element 132 and the end ofthe bore 124. The wash head has a cylindrical boss portion 133 extendinginto the bore 124 as far as the passage 123. At its outer face the washhead 102 has a recess coaxial with the shaft 126,

the wall of the recess defining a core clutch face 134 adapted tocooperate with the clutch element 132. The outer surface of the bossportion 133 is provided with an O-ring seal 135 and sufficient clearanceis provided between the clutch element 132 and the end of the bore 124to permit limited axial sliding movement of the wash head 102 on theshaft 126.

At a position inwardly of the seal 135, the boss portion 133 is providedwith an external annular recess 136 into which a series of holes 137vent from the interior of the boss. The holes 137 also act as astrainer. A passage 138 formed in the body 101 extends form the annularzone in which the recess 136 in the boss rotates and terminates at theinternal wall 118. A removable nozzle member 139 is mounted in thePelton wheel compartment 122 and in communication with the passage 138,by a set screw 140.

The static shaft 113 extends downwardly through a gland structure 141incorporating two external and two internal 0- ring seals 142 and 143respectively and which is vented from a central annular recess by a vent144. At its lower end, the static shaft 113 is journaled in a thrustbearing 145 set in the internal wall 117 and adapted to transfer thefull weight of the machine onto the shaft 113. The thrust bearing 145 isenclosed by a cover plate 146 and may comprise a ball race generally asindicated in FIG. 6. Alternatively, a dry lubricated bearing may be usedas described with reference to the embodiment of FIGS. 1 to 4.

A pinion 147 is keyed on the shaft 113 and secured by a nut 148 at aposition within the chamber 120 immediately above the thrust bearing145. The pinion 147 carries an upwardly extending stepped sleeve bushing149 on which is keyed a quadrant plate 150. Mounted for rotation on theshaft 113 above the quadrant plate on a spacer washer (not shown), is aworm wheel 151 having an upwardly extending sleeve bushing 152 formed asa bevel pinion 153 at its upper end, the bevel pinion 153 meshes withthe crown wheel 127.

At a position spaced radially from the shaft (see FIG. 7), the quadrantplate carries two bearing brackets 154 in which the spindle ofa worm 155is journaled, the worm meshing with the worm wheel 151, At one end, thespindle of the worm extends through the respective bracket 154 and has apinion 156 keyed thereto. The pinion 156 meshes with a pinion 157 keyedon the end of a spindle 158, the spindle 148 being journaled in afurther bearing bracket 159 on the quadrant plate 150. The other end ofthe spindle 148 has a six lobed star wheel 160 keyed thereto, the starwheel 160 having its axis lying on an extended radius of the shaft 113.

Mounted in the body portion 101, also on an extended radius of the shaft113 but above the axis of the star wheel 160, is a striker pin 161. Thestriker pin 161 is threaded at its outer end for adjustment and extendsinwardly to such a position that upon rotation of the body portion 101about the shaft 113 (as described below) the pin 161 strikes one of thelobes of the star wheel 160 to cause partial rotation of the star wheel160, the partial rotation being transmitted through the gears 157, 156,155, 151, 153 and 127 to the shaft 126 and the wash head 102 to effectan acceleration or a deceleration of the rotational speed of the washhead 2. g

The pinion 147 meshes with a smaller pinion 162 keyed to the upper endof a vertical shaft 163. The shaft 16;} extends downwardly through asleeve bearing 164 in the inner wall 117, the bearing 164 incorporatinginner and outer seals 165.

At its lower end, (See FIG. 6 and 8) in the transmission gear chamber121, the shaft 163 is provided with a socket 166 which envelops the endof a shaft 167 having a worm wheel 168 keyed thereto. A drive connectionbetween the socket 166 and the shaft 167 is provided by a shear pin 169extending transversely through both elements. The lower end of the shaft167 is journaled in a bearing 170 formed in the wall 118. A worm 171(FIG. 8) meshes with the worm wheel 168 and is keyed to a shaft 172 ofwhich one end is journaled in a bearing 173 formed in the outer wall ofthe body 101 and the other end extends through a bearing block 174mounted on the wall 118. A further worm wheel 175 is keyed to the otherend of the shaft 172 and meshes with a worm 176. The worm 176 is keyedto a vertical shaft 177 which at its upper end is journaled in a bearing178 in a bracket 179 bolted to the wall 118. The transmission gearchamber 121 is preferably packed with grease.

The lower end of the shaft 177 extends downwardly through a bearing 180in the inner wall 118 and into the Pelton wheel compartment 122, where aPelton wheel 181 is keyed or splined on the shaft 177 and secured by anut 182.

The lower wall of the body 101 is formed by a detachable cover 183having a discharge port 184 for exhaust water from the Pelton wheel 181.

The machine is assembled, as indicated in FIG, 6, in tiered sectionssecured together by set screws 185. This arrangement enables a machineto be provided which whilst having an output sufficient to operationalrequirements, can be passed through the standard 12.5 inch (32centimeter) access holes which are normally provided in the tanks ofmarine oil tankers.

The machine shown in FIG. 6 to 8 is advantageously secured by the flange104 to the flange of a wash fluid supply pipe. At this stage, and duringthe lowering of the machine through the access hole, the wash head 102is free to rotate with respect to its fixed clutch elements 132. Thisprevents damage to the internal gearing due to torque inadvertently orimproperly applied to the wash head 2 and also permits orientation ofthe nozzles 103 to allow the wash head to pass through the access hole.

Similarly, before lowering into the tank and during positioning when inthe tank, the clutch 106/111 allows rotation of the body 101 relative tothe wash water supply pipe which again prevents damage to the internalgearing.

In operation, and after proper location in the tank, as soon as washfluid under pressure enters the chamber 119, it is directed down thepassage 123, through the bore 124 and boss 133, and out through thenozzles 103. The optimum water pressure is approximately 200 pounds persquare inch (14,000 gm./cm. and at this pressure, the pressure loadingson the upwardly presented face of the inner wall 116 and the innersurfaces of the wash head 102 are sufficient to engage the clutches106/111 and 132/134 and prevent relative rotation between the parts.

A proportion of the wash fluid entering the boss 133 is bled offradially through the holes 137 into the annular external recess 136 inthe boss. This wash fluid is then led through the passage 138 anddischarged through the nozzle 139. The fluid discharged impinges on thebuckets of the Pelton wheel to cause rotation thereof and is thendischarged through the port 184 in the lower cover 183.

The rotation of the Pelton wheel is transmitted through the gear train176, 175, 171 and 168 to the pinion 162 so as to preferably provide aspeed reduction of approximately 100:1 from the Pelton wheel speed.Since the pinion 147 is keyed to the static shaft 113, the pinion 162carries out a planetary motion with respect to the pinion 147 andthereby causes the body 101 to rotate around the shaft 113.

The initial rotation of the body 101 causes the crown wheel 127 torotate due to its engagement with the bevel pinion 153. The bevel pinion153 is prevented from rotation by the locking action of the worm 155 onthe worm gear 151 when reverse drive is applied.

As the body 101 continues to move around the shaft 113, the striker pin161 (FIG. 7) strikes one of the lobes of the star wheel 160, and causes,through the gears 157, 156, the worm 155, the worm wheel 151, and thebevel pinion 153, a momentary acceleration of the crown wheel 127together with the shaft 126 and the wash head 102. The frequency withwhich this acceleration occurs can be varied by increasing or decreasingthe number of lobes on the star wheel and/or the number of striker pinsset in the body I. The acceleration can also be varied by changing thegear ratios between the star wheel 160 and the crown wheel 127.

in consequence of the momentary acceleration, the jets from the nozzles103 are precessed slightly at each passage round the walls of the tankso that the whole zone of the tank surface covered by the machine iseventually washed.

In all of the embodiments above described, the wash fluid discharge headis preferably arranged to rotate at a speed (neglecting the momentaryaccelerations) slower than that of the body portion 1. The paths ofimpingement of the jets are then more effective in removing residuesfrom horizontal surfaces in the tank.

In one machine having a jet range of approximately 120 feet (37 meters)the body 101 rotates about the vertical axis on the shaft 126 at 1.5revolutions per minute whilst the wash fluid discharge head 2 rotatesabout the horizontal axis of the shaft 126 at 0.5 revolutions perminute. in a smaller machine having a jet range of approximately 55 feet(17 meters) the body 101 rotates at 3 revolutions per minute whilst thewash fluid discharge head 2 rotates at l revolution per minute.

I claim:

1. A machine for washing the interior surface of a hollow structurecomprising a head assembly, means for mounting the head assembly forrotation about a first axis, a wash fluid discharge head mounted on saidhead assembly for rotation with respect thereto about a second axis atan angle to said first axis, a passage in said head assembly forreceiving and transfering wash fluid to said wash fluid discharge head,wash fluid actuated rotary drive means mounted on said head assemblyexternally of said passage, a fluid feed passage extending from saidfirst passage to said drive means, and transmission means connected tosaid drive means to effect simultaneous rotational movement of said headassembly about said first axis, and said wash fluid discharge head aboutsaid second axis, said transmission means including means for effectingintermittent accelerations or decelerations in the rotational speed ofsaid wash fluid discharge head relative to the rotational speed of saidhead assembly.

2. A machine as claimed in claim 1, wherein said transmission meanscomprise a static shaft, a first gear mounted for rotation on saidshaft, a second gear mounted for driving said wash fluid discharge headand meshing with said first gear, a third gear secured on said shaft,reduction gear means connecting said drive means to said third gear forcausing rotation of said head assembly around said shaft, meansresisting rotation of said first gear by said second gear so that saidsecond gear is driven inconsequence of the rotation of said head assembly, a rotary lobed element connected for driving said first gear,and striker means mounted in said head assembly for repeated engagementwith said lobed element during rotation of the assembly wherebyintermittent accelerations or decelerations of said first and secondgears are effected.

3. A machine as claimed in claim 2, wherein the means re sisting therotation of the first gear comprises a friction clutch.

4. A machine as claimed in claim 2, wherein the means resisting therotation of the first gear comprises a worm meshed ll!!! awmlhsslm q fortetiti s it .thsfie! gear 5. A machine as claimed in claim 4, whereinthe worm is mounted on a spindle connected through a gear train to afurther spindle carrying said lobed element, said further spindle beingdisposed radially with respect to said static shaft.

6. A machine as claimed in claim 2 in which the means mounting the headassembly for rotation comprises a pipe having a flange at one endadapted to bolted to a flange of a wash fluid supply pipe, said pipecomprising at its other end an internal support member to which theupper end of said static shaft is coaxially secured, said other endbeing received within a tubular inlet portion of said head assembly.

7. A machine as claimed in claim 6, wherein said pipe is divided intotwo annular portions and wherein said annular portions are connected bya friction clutch.

8. A machine for washing the interior surface of a hollow structure,comprising, in combination, a head assembly having a body member havingan inlet passage, an outlet passage defining a bore a passageinterconnecting said inlet and outlet passages, a first inner walldividing said passages from a gear chamber, a second inner wall dividingsaid gear chamber from a Pelton wheel compartment having an exhaust parttherein, an inlet pipe received at one end in said inlet chamber forrotation of said body with respect thereto, a flange on the other end ofsaid inlet pipe for secural to a flange of a wash fluid supply pipe, athrust bearing located at a transverse wall of said body member beneathsaid first inner wall, a sealing gland mounted in said first inner wallin axial alignment with said, thrust bearing, a static shaft carrying atits lower end the weight of said body through said thrust bearing andextending upwardly through said sealing gland, means supporting theupper end of said shaft coaxially in said inlet pipe, a first gearmounted for rotation on said static shaft a second gear meshing withsaid first gear and operatively connected through sealing means in saidfirst inner wall with a wash fluid discharge head mounted for rotationin said outlet bore, a third gear secured on said static shaft, a Peltonwheel mounted for rotation in said Pelton Wheel compartment, reductiongear means connecting said Pelton wheel to said third gear for causingrotation of said head assembly around said shaft means resistingrotation of the first gear by said second gear, so that said second gearis driven in consequence of the rotation of said head assembly, a rotarylobed element connected for driving said first gear, striker meansmounted in said head assembly for repeated engagement with said lobedelement whereby intermittent accelerations or decelerations of saidfirst and second gears are effected, and means defining a fluid feedpassage extending between one of said first mentioned passages and saidPelton Wheel compartment and terminating in a nozzle or nozzles disposedfor directing impulse jets at the buckets of the wheel.

9. A machine as claimed in claim 8, wherein the means resisting therotation of the first gear comprises a friction clutch.

10. A machine as claimed in claim 8, wherein the means for resisting therotation of the first gear comprises a worm meshed with a worm wheelmounted for rotation with the first gear.

11. A machine as claimed in claim 8, wherein said Pelton wheelcompartment is mounted at the lower end of the head assembly and whereinthe third gear is driven by a pinion connected to said Pelton wheelthrough a two stage worm and wheel reduction gear train located in acompartment intermediate said transverse wall and second inner wall.

12. A machine as claimed in claim 8, wherein said wash fluid dischargehead is connected to said second gear through means comprisiga frictionclutch.

1. A machine for washing the interior surface of a hollow structurecomprising a head assembly, means for mounting the head assembly forrotation about a first axis, a wash fluid discharge head mounted on saidhead assembly for rotation with respect thereto about a second axis atan angle to said first axis, a passage in said head assembly forreceiving and transfering wash fluid to said wash fluid discharge head,wash fluid actuated rotary drive meAns mounted on said head assemblyexternally of said passage, a fluid feed passage extending from saidfirst passage to said drive means, and transmission means connected tosaid drive means to effect simultaneous rotational movement of said headassembly about said first axis, and said wash fluid discharge head aboutsaid second axis, said transmission means including means for effectingintermittent accelerations or decelerations in the rotational speed ofsaid wash fluid discharge head relative to the rotational speed of saidhead assembly.
 2. A machine as claimed in claim 1, wherein saidtransmission means comprise a static shaft, a first gear mounted forrotation on said shaft, a second gear mounted for driving said washfluid discharge head and meshing with said first gear, a third gearsecured on said shaft, reduction gear means connecting said drive meansto said third gear for causing rotation of said head assembly aroundsaid shaft, means resisting rotation of said first gear by said secondgear so that said second gear is driven inconsequence of the rotation ofsaid head assembly, a rotary lobed element connected for driving saidfirst gear, and striker means mounted in said head assembly for repeatedengagement with said lobed element during rotation of the assemblywhereby intermittent accelerations or decelerations of said first andsecond gears are effected.
 3. A machine as claimed in claim 2, whereinthe means resisting the rotation of the first gear comprises a frictionclutch.
 4. A machine as claimed in claim 2, wherein the means resistingthe rotation of the first gear comprises a worm meshed with a worm wheelmounted for rotation with the first gear.
 5. A machine as claimed inclaim 4, wherein the worm is mounted on a spindle connected through agear train to a further spindle carrying said lobed element, saidfurther spindle being disposed radially with respect to said staticshaft.
 6. A machine as claimed in claim 2 in which the means mountingthe head assembly for rotation comprises a pipe having a flange at oneend adapted to bolted to a flange of a wash fluid supply pipe, said pipecomprising at its other end an internal support member to which theupper end of said static shaft is coaxially secured, said other endbeing received within a tubular inlet portion of said head assembly. 7.A machine as claimed in claim 6, wherein said pipe is divided into twoannular portions and wherein said annular portions are connected by afriction clutch.
 8. A machine for washing the interior surface of ahollow structure, comprising, in combination, a head assembly having abody member having an inlet passage, an outlet passage defining a bore apassage interconnecting said inlet and outlet passages, a first innerwall dividing said passages from a gear chamber, a second inner walldividing said gear chamber from a Pelton wheel compartment having anexhaust part therein, an inlet pipe received at one end in said inletchamber for rotation of said body with respect thereto, a flange on theother end of said inlet pipe for secural to a flange of a wash fluidsupply pipe, a thrust bearing located at a transverse wall of said bodymember beneath said first inner wall, a sealing gland mounted in saidfirst inner wall in axial alignment with said, thrust bearing, a staticshaft carrying at its lower end the weight of said body through saidthrust bearing and extending upwardly through said sealing gland, meanssupporting the upper end of said shaft coaxially in said inlet pipe, afirst gear mounted for rotation on said static shaft a second gearmeshing with said first gear and operatively connected through sealingmeans in said first inner wall with a wash fluid discharge head mountedfor rotation in said outlet bore, a third gear secured on said staticshaft, a Pelton wheel mounted for rotation in said Pelton Wheelcompartment, reduction gear means connecting said Pelton wheel to saidthird gear for causing rotation of said head assembly around said shaftmeans resisting rotation of the first gear by said second gear, so thatsaid second gear is driven in consequence of the rotation of said headassembly, a rotary lobed element connected for driving said first gear,striker means mounted in said head assembly for repeated engagement withsaid lobed element whereby intermittent accelerations or decelerationsof said first and second gears are effected, and means defining a fluidfeed passage extending between one of said first mentioned passages andsaid Pelton Wheel compartment and terminating in a nozzle or nozzlesdisposed for directing impulse jets at the buckets of the wheel.
 9. Amachine as claimed in claim 8, wherein the means resisting the rotationof the first gear comprises a friction clutch.
 10. A machine as claimedin claim 8, wherein the means for resisting the rotation of the firstgear comprises a worm meshed with a worm wheel mounted for rotation withthe first gear.
 11. A machine as claimed in claim 8, wherein said Peltonwheel compartment is mounted at the lower end of the head assembly andwherein the third gear is driven by a pinion connected to said Peltonwheel through a two stage worm and wheel reduction gear train located ina compartment intermediate said transverse wall and second inner wall.12. A machine as claimed in claim 8, wherein said wash fluid dischargehead is connected to said second gear through means comprising afriction clutch.